1. Field of the Invention
The present invention relates to light emitting diode (LED) signals, specifically to an LED symbol signal with a uniform display aspect despite having a reduced number of LEDs.
2. Description of Related Art
Symbol signals, for example turn signals, pedestrian signals, and walk/don't walk signals previously have been designed with incandescent point light sources in a housing with a mask covering. The mask defining the symbol desired. Incandescent bulbs suffer from drawbacks of high power consumption and the requirement for frequent maintenance as the bulbs burn out.
LED symbol signals have reduced maintenance and operating costs due to the extreme life span of LEDs and their low power consumption in comparison to incandescent bulbs. Previously, LEDs were used to form the symbol desired by filling the symbol space with a full matrix of LEDs. As new, improved generations of LEDs become available, they emit more light from each individual LED. Therefore, the full matrix of LEDs is not required to create a suitably bright signal. The LEDs may then be spaced further apart from each other, omitting LEDs thereby saving material costs and lowering the signals operating power consumption. However, as the LEDs spacing increases, an undesirable “pixel effect” appears in which the individual LEDs become increasingly discernable to the viewer.
An object of the present invention is to provide a high efficiency and cost effective LED symbol with a reduced or eliminated “pixel effect”. A further object of this invention is to provide a LED symbol signal with a design that may be easily modified as new generations of LEDs with increased light output become available, reducing the number of LEDs required to achieve a similar light output level.